Synnefo » snf-ganeti

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#

# Copyright (C) 2006, 2007, 2008 Google Inc.

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# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

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# This program is distributed in the hope that it will be useful, but

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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

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# You should have received a copy of the GNU General Public License

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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Global Configuration data for Ganeti.

This module provides the interface to a special case of cluster

configuration data, which is mostly static and available to all nodes.

"""

import sys

import re

from ganeti import errors

from ganeti import constants

from ganeti import utils

from ganeti import serializer

SSCONF_LOCK_TIMEOUT = 10

RE_VALID_SSCONF_NAME = re.compile(r'^[-_a-z0-9]+$')

class SimpleConfigReader(object):

  """Simple class to read configuration file.

  """

  def __init__(self, file_name=constants.CLUSTER_CONF_FILE):

    """Initializes this class.

    @type file_name: string

    @param file_name: Configuration file path

    """

    self._file_name = file_name

    self._config_data = serializer.Load(utils.ReadFile(file_name))

    # TODO: Error handling

  def GetClusterName(self):

    return self._config_data["cluster"]["cluster_name"]

  def GetHostKey(self):

    return self._config_data["cluster"]["rsahostkeypub"]

  def GetMasterNode(self):

    return self._config_data["cluster"]["master_node"]

  def GetMasterIP(self):

    return self._config_data["cluster"]["master_ip"]

  def GetMasterNetdev(self):

    return self._config_data["cluster"]["master_netdev"]

  def GetFileStorageDir(self):

    return self._config_data["cluster"]["file_storage_dir"]

  def GetHypervisorType(self):

    return self._config_data["cluster"]["hypervisor"]

  def GetNodeList(self):

    return self._config_data["nodes"].keys()

  @classmethod

  def FromDict(cls, val, cfg_file=constants.CLUSTER_CONF_FILE):

    """Alternative construction from a dictionary.

    """

    obj = SimpleConfigReader.__new__(cls)

    obj._config_data = val

    obj._file_name = cfg_file

    return obj

class SimpleConfigWriter(SimpleConfigReader):

  """Simple class to write configuration file.

  """

  def SetMasterNode(self, node):

    """Change master node.

    """

    self._config_data["cluster"]["master_node"] = node

  def Save(self):

    """Writes configuration file.

    Warning: Doesn't take care of locking or synchronizing with other

    processes.

    """

    utils.WriteFile(self._file_name,

                    data=serializer.Dump(self._config_data),

                    mode=0600)

def _SsconfPath(name):

  if not RE_VALID_SSCONF_NAME.match(name):

    raise errors.ParameterError("Invalid ssconf name: %s" % name)

  return "%s/ssconf_%s" % (constants.DATA_DIR, name)

def WriteSsconfFiles(values):

  """Writes legacy ssconf files to be used by external scripts.

  @type values: dict

  @param values: Dictionary of (name, value)

  """

  ssconf_lock = utils.FileLock(constants.SSCONF_LOCK_FILE)

  # Get lock while writing files

  ssconf_lock.Exclusive(blocking=True, timeout=SSCONF_LOCK_TIMEOUT)

  try:

    for name, value in values.iteritems():

      if not value.endswith("\n"):

        value += "\n"

      utils.WriteFile(_SsconfPath(name),

                      data=value)

  finally:

    ssconf_lock.Unlock()

def GetMasterAndMyself(ss=None):

  """Get the master node and my own hostname.

  This can be either used for a 'soft' check (compared to CheckMaster,

  which exits) or just for computing both at the same time.

  The function does not handle any errors, these should be handled in

  the caller (errors.ConfigurationError, errors.ResolverError).

  """

  if ss is None:

    ss = SimpleConfigReader()

  return ss.GetMasterNode(), utils.HostInfo().name

def CheckMaster(debug, ss=None):

  """Checks the node setup.

  If this is the master, the function will return. Otherwise it will

  exit with an exit code based on the node status.

  """

  try:

    master_name, myself = GetMasterAndMyself(ss)

  except errors.ConfigurationError, err:

    print "Cluster configuration incomplete: '%s'" % str(err)

    sys.exit(constants.EXIT_NODESETUP_ERROR)

  except errors.ResolverError, err:

    sys.stderr.write("Cannot resolve my own name (%s)\n" % err.args[0])

    sys.exit(constants.EXIT_NODESETUP_ERROR)

  if myself != master_name:

    if debug:

      sys.stderr.write("Not master, exiting.\n")

    sys.exit(constants.EXIT_NOTMASTER)